xref: /aosp_15_r20/external/tink/cc/util/buffer.cc (revision e7b1675dde1b92d52ec075b0a92829627f2c52a5)
1*e7b1675dSTing-Kang Chang // Copyright 2019 Google Inc.
2*e7b1675dSTing-Kang Chang //
3*e7b1675dSTing-Kang Chang // Licensed under the Apache License, Version 2.0 (the "License");
4*e7b1675dSTing-Kang Chang // you may not use this file except in compliance with the License.
5*e7b1675dSTing-Kang Chang // You may obtain a copy of the License at
6*e7b1675dSTing-Kang Chang //
7*e7b1675dSTing-Kang Chang //     http://www.apache.org/licenses/LICENSE-2.0
8*e7b1675dSTing-Kang Chang //
9*e7b1675dSTing-Kang Chang // Unless required by applicable law or agreed to in writing, software
10*e7b1675dSTing-Kang Chang // distributed under the License is distributed on an "AS IS" BASIS,
11*e7b1675dSTing-Kang Chang // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12*e7b1675dSTing-Kang Chang // See the License for the specific language governing permissions and
13*e7b1675dSTing-Kang Chang // limitations under the License.
14*e7b1675dSTing-Kang Chang //
15*e7b1675dSTing-Kang Chang ///////////////////////////////////////////////////////////////////////////////
16*e7b1675dSTing-Kang Chang 
17*e7b1675dSTing-Kang Chang #include "tink/util/buffer.h"
18*e7b1675dSTing-Kang Chang 
19*e7b1675dSTing-Kang Chang #include <memory>
20*e7b1675dSTing-Kang Chang 
21*e7b1675dSTing-Kang Chang #include "absl/memory/memory.h"
22*e7b1675dSTing-Kang Chang #include "absl/status/status.h"
23*e7b1675dSTing-Kang Chang #include "tink/util/status.h"
24*e7b1675dSTing-Kang Chang #include "tink/util/statusor.h"
25*e7b1675dSTing-Kang Chang 
26*e7b1675dSTing-Kang Chang namespace crypto {
27*e7b1675dSTing-Kang Chang namespace tink {
28*e7b1675dSTing-Kang Chang namespace util {
29*e7b1675dSTing-Kang Chang namespace {
30*e7b1675dSTing-Kang Chang 
31*e7b1675dSTing-Kang Chang class OwningBuffer : public Buffer {
32*e7b1675dSTing-Kang Chang  public:
33*e7b1675dSTing-Kang Chang   // Constructs a new Buffer which allocates a new memory block
34*e7b1675dSTing-Kang Chang   // of size 'allocated_size' and uses it for the actual data.
35*e7b1675dSTing-Kang Chang   // The allocated memory block is owned by this Buffer.
36*e7b1675dSTing-Kang Chang   // It is assumed that 'allocated_size' is positive.
OwningBuffer(int allocated_size)37*e7b1675dSTing-Kang Chang   explicit OwningBuffer(int allocated_size)
38*e7b1675dSTing-Kang Chang       : allocated_size_(allocated_size), size_(allocated_size) {
39*e7b1675dSTing-Kang Chang     owned_mem_block_ = absl::make_unique<char[]>(allocated_size);
40*e7b1675dSTing-Kang Chang   }
41*e7b1675dSTing-Kang Chang 
get_mem_block() const42*e7b1675dSTing-Kang Chang   char* const get_mem_block() const override  {
43*e7b1675dSTing-Kang Chang     return owned_mem_block_.get();
44*e7b1675dSTing-Kang Chang   }
45*e7b1675dSTing-Kang Chang 
allocated_size() const46*e7b1675dSTing-Kang Chang   int allocated_size() const override { return allocated_size_; }
47*e7b1675dSTing-Kang Chang 
size() const48*e7b1675dSTing-Kang Chang   int size() const override { return size_; }
49*e7b1675dSTing-Kang Chang 
set_size(int new_size)50*e7b1675dSTing-Kang Chang   util::Status set_size(int new_size) override {
51*e7b1675dSTing-Kang Chang     if (new_size < 0  || new_size > allocated_size_) {
52*e7b1675dSTing-Kang Chang       return Status(absl::StatusCode::kInvalidArgument,
53*e7b1675dSTing-Kang Chang                     "new_size must satisfy 0 <= new_size <= allocated_size()");
54*e7b1675dSTing-Kang Chang     }
55*e7b1675dSTing-Kang Chang     size_ = new_size;
56*e7b1675dSTing-Kang Chang     return OkStatus();
57*e7b1675dSTing-Kang Chang   }
58*e7b1675dSTing-Kang Chang 
59*e7b1675dSTing-Kang Chang   ~OwningBuffer() override = default;
60*e7b1675dSTing-Kang Chang 
61*e7b1675dSTing-Kang Chang  private:
62*e7b1675dSTing-Kang Chang   std::unique_ptr<char[]> owned_mem_block_;
63*e7b1675dSTing-Kang Chang   const int allocated_size_;
64*e7b1675dSTing-Kang Chang   int size_;
65*e7b1675dSTing-Kang Chang };
66*e7b1675dSTing-Kang Chang 
67*e7b1675dSTing-Kang Chang 
68*e7b1675dSTing-Kang Chang class NonOwningBuffer : public Buffer {
69*e7b1675dSTing-Kang Chang  public:
70*e7b1675dSTing-Kang Chang   // Constructs a new Buffer which uses the given 'mem_block' as a buffer
71*e7b1675dSTing-Kang Chang   // for the actual data.
72*e7b1675dSTing-Kang Chang   // Does NOT take the ownership of 'mem_block' which must be non-null,
73*e7b1675dSTing-Kang Chang   // must allocate at least 'allocated_size' bytes, and must remain alive
74*e7b1675dSTing-Kang Chang   // as long as the returned Buffer is in use.
75*e7b1675dSTing-Kang Chang   // It is assumed that 'mem_block' is non-null, and that
76*e7b1675dSTing-Kang Chang   // 'allocated_size' is positive.
NonOwningBuffer(char * mem_block,int allocated_size)77*e7b1675dSTing-Kang Chang   NonOwningBuffer(char* mem_block, int allocated_size)
78*e7b1675dSTing-Kang Chang       : mem_block_(mem_block),
79*e7b1675dSTing-Kang Chang         allocated_size_(allocated_size), size_(allocated_size) {}
80*e7b1675dSTing-Kang Chang 
get_mem_block() const81*e7b1675dSTing-Kang Chang   char* const get_mem_block() const override { return mem_block_; };
82*e7b1675dSTing-Kang Chang 
allocated_size() const83*e7b1675dSTing-Kang Chang   int allocated_size() const override { return allocated_size_; }
84*e7b1675dSTing-Kang Chang 
size() const85*e7b1675dSTing-Kang Chang   int size() const override { return size_; }
86*e7b1675dSTing-Kang Chang 
set_size(int new_size)87*e7b1675dSTing-Kang Chang   util::Status set_size(int new_size) override {
88*e7b1675dSTing-Kang Chang     if (new_size < 0  || new_size > allocated_size_) {
89*e7b1675dSTing-Kang Chang       return Status(absl::StatusCode::kInvalidArgument,
90*e7b1675dSTing-Kang Chang                     "new_size must satisfy 0 <= new_size <= allocated_size()");
91*e7b1675dSTing-Kang Chang     }
92*e7b1675dSTing-Kang Chang     size_ = new_size;
93*e7b1675dSTing-Kang Chang     return OkStatus();
94*e7b1675dSTing-Kang Chang   }
95*e7b1675dSTing-Kang Chang 
96*e7b1675dSTing-Kang Chang   ~NonOwningBuffer() override = default;
97*e7b1675dSTing-Kang Chang 
98*e7b1675dSTing-Kang Chang  private:
99*e7b1675dSTing-Kang Chang   char* const mem_block_;
100*e7b1675dSTing-Kang Chang   const int allocated_size_;
101*e7b1675dSTing-Kang Chang   int size_;
102*e7b1675dSTing-Kang Chang };
103*e7b1675dSTing-Kang Chang 
104*e7b1675dSTing-Kang Chang }  // namespace
105*e7b1675dSTing-Kang Chang 
106*e7b1675dSTing-Kang Chang // static
New(int allocated_size)107*e7b1675dSTing-Kang Chang StatusOr<std::unique_ptr<Buffer>> Buffer::New(int allocated_size) {
108*e7b1675dSTing-Kang Chang   if (allocated_size <= 0) {
109*e7b1675dSTing-Kang Chang     return Status(absl::StatusCode::kInvalidArgument,
110*e7b1675dSTing-Kang Chang                   "allocated_size must be positive");
111*e7b1675dSTing-Kang Chang   }
112*e7b1675dSTing-Kang Chang   return {absl::make_unique<OwningBuffer>(allocated_size)};
113*e7b1675dSTing-Kang Chang }
114*e7b1675dSTing-Kang Chang 
115*e7b1675dSTing-Kang Chang // static
NewNonOwning(char * mem_block,int allocated_size)116*e7b1675dSTing-Kang Chang StatusOr<std::unique_ptr<Buffer>> Buffer::NewNonOwning(
117*e7b1675dSTing-Kang Chang     char* mem_block, int allocated_size) {
118*e7b1675dSTing-Kang Chang   if (allocated_size <= 0) {
119*e7b1675dSTing-Kang Chang     return Status(absl::StatusCode::kInvalidArgument,
120*e7b1675dSTing-Kang Chang                   "allocated_size must be positive");
121*e7b1675dSTing-Kang Chang   }
122*e7b1675dSTing-Kang Chang   if (mem_block == nullptr) {
123*e7b1675dSTing-Kang Chang     return Status(absl::StatusCode::kInvalidArgument,
124*e7b1675dSTing-Kang Chang                   "mem_block must be non-null");
125*e7b1675dSTing-Kang Chang   }
126*e7b1675dSTing-Kang Chang   return {absl::make_unique<NonOwningBuffer>(mem_block, allocated_size)};
127*e7b1675dSTing-Kang Chang }
128*e7b1675dSTing-Kang Chang 
129*e7b1675dSTing-Kang Chang 
130*e7b1675dSTing-Kang Chang }  // namespace util
131*e7b1675dSTing-Kang Chang }  // namespace tink
132*e7b1675dSTing-Kang Chang }  // namespace crypto
133